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首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >A 2,300-year-long annually resolved record of the South American summer monsoon from the Peruvian Andes
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A 2,300-year-long annually resolved record of the South American summer monsoon from the Peruvian Andes

机译：秘鲁安第斯山脉每年记录的长达2300年的南美夏季风记录

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摘要

Decadal and centennial mean state changes in South American summer monsoon (SASM) precipitation during the last 2,300 years are detailed using an annually resolved authigenic calcite record of precipitation δ~(18)O from a varved lake in the Central Peruvian Andes. This unique sediment record shows that δ~(18)O peaked during the Medieval Climate Anomaly (MCA) from A.D. 900 to 1100, providing evidence that the SASM weakened considerably during this period. Minimum δ~(18)O values occurred during the Little Ice Age (LIA) between A.D. 1400 and 1820, reflecting a prolonged intensification of the SASM that was regionally synchronous. After the LIA, δ~(18)O increased rapidly, particularly during the current warm period (CWP; A.D. 1900 to present), indicating a return to reduced SASM precipitation that was more abrupt and sustained than the onset of the MCA. Diminished SASM precipitation during the MCA and CWP tracks reconstructed Northern Hemisphere and North Atlantic warming and a northward displacement of the Intertropi-cal Convergence Zone (ITCZ) over the Atlantic, and likely the Pacific. Intensified SASM precipitation during the LIA follows reconstructed Northern Hemisphere and North Atlantic cooling, El Nino-like warming in the Pacific, and a southward displacement of the ITCZ over both oceans. These results suggest that SASM mean state changes are sensitive to ITCZ variability as mediated by Western Hemisphere tropical sea surface temperatures, particularly in the Atlantic. Continued Northern Hemisphere and North Atlantic warming may therefore help perpetuate the recent reductions in SASM precipitation that characterize the last 100 years, which would negatively impact Andean water resources.
机译：使用每年解析的秘鲁中部安第斯山脉中压湖中δ〜（18）O的自生方解石记录，详细描述了过去2300年内南美夏季风（SASM）降水的年代际和百年平均状态变化。这一独特的沉积物记录表明，δ〜（18）O在公元900年至1100年的中世纪气候异常（MCA）期间达到峰值，这提供了SASM在此期间显着减弱的证据。最小δ〜（18）O值发生在公元1400年至1820年的小冰期（LIA）期间，反映了区域同步SASM的长时间强化。在LIA之后，δ〜（18）O迅速增加，特别是在当前暖期（CWP; 1900年至今）期间，这表明SASM降水恢复减少，比MCA的发作更为突然和持续。在MCA和CWP轨道期间，SASM降水减少，重建了北半球和北大西洋的变暖，以及大西洋（可能是太平洋）上的热带对流收敛带（ITCZ）向北移动。在LIA期间，SASM的降水增加，是由于北半球和北大西洋的重建，太平洋上像厄尔尼诺现象一样的变暖以及ITCZ在两个海洋上的南移。这些结果表明，SASM平均状态变化对由西半球热带海表温度（特别是在大西洋）介导的ITCZ变异敏感。因此，北半球和北大西洋持续升温可能有助于使最近100年以来SASM降水量的最近减少持续下去，这将对安第斯水源造成负面影响。

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    Broxton W. Bird; Mark B. Abbott; Mathias Vuille; Donald T. Rodbell; Nathan D. Stansell; Michael F. Rosenmeier;

  • 作者单位

    Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, PA 15260;

    Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, PA 15260;

    Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222;

    Geology Department, Union College, 807 Union Street, Schenectady, NY 12308;

    Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, PA 15260;

    Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, PA 15260;

  • 收录信息 美国《科学引文索引》(SCI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
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  • 关键词

    oxygen isotopes; varves; tropical hydroclimate;

    机译：氧同位素脉;热带水气候;

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